lfp.thy
author lcp
Fri, 19 Aug 1994 11:10:56 +0200
changeset 116 ab4328bbff70
parent 0 7949f97df77a
permissions -rw-r--r--
HOL/subset.thy, equalities.thy, mono.thy: new HOL/Lfp.thy: now depends upon mono HOL/Gfp.thy: depends upon Lfp, not just mono
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(*  Title: 	HOL/lfp.thy
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    ID:         $Id$
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    Author: 	Lawrence C Paulson, Cambridge University Computer Laboratory
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    Copyright   1992  University of Cambridge
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The Knaster-Tarski Theorem
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*)
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Lfp = Sum +
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consts lfp :: "['a set=>'a set] => 'a set"
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rules
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 (*least fixed point*)
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 lfp_def "lfp(f) == Inter({u. f(u) <= u})"
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end